The trailhead at Althengstett leads for a few meters over (fine) gravel, but after that, you're completely free from traffic (except for agricultural areas).
A beautiful connecting trail between Althengstett, Ostelsheim, and Gechingen. At the farm, you can enjoy a seemingly endless view over the fields.
The surface is good and undamaged, but there are a few bumps here and there caused by roots pushing through.